Background: Molecular typing allows a rapid and precise species differentiation and is essential in investigating the spread of specific genotypes and any relationship with drug resistance. Methodology: To compare the...Background: Molecular typing allows a rapid and precise species differentiation and is essential in investigating the spread of specific genotypes and any relationship with drug resistance. Methodology: To compare the discrimination power of 24-loci Mycobacteria interspersed repetitive units-variable number of tandem repeat (MIRU-VNTR) to spoligotyping in determining the circulating genotypes of Mycobacterium tuberculosis in isolates from pulmonary tuberculosis patients in Kenya, a total of 204 isolates were typed. Results: Spoligotyping identified 22 spoligo lineages;while 36(17.6%) isolates were not determined. MIRU-VNTR typing identified 12 genotypes;Kenya H37_Rv_ like, S-like that had never been reported before and which were not identified by spoligotyping were identified. Others were Uganda I and II, LAM, Beijing, TUR, EAI, Delhi/C, S and Haarlem. Only 8 (3.9%) were not defined by MIRU-VNTR. Delhi/CAS, EAI, S, S-like, LAM and Beijing had strains that showed resistance to all the five drugs tested. Two strains of EAI and 2 of S genotypes were resistant to all the five drugs tested. Beijing genotype commonly associated with drug resistance was found to be third in drug resistance (14.7%) after Delhi/CAS (28.9%) and LAM (17.6%) with the highest resistance towards isoniazid and pyrazinamide (3.9% each). MIRU-VNTR typing was more discriminative than spoligotyping;identifying 10 unique H37_Rv-like isolates designated KeniaH37_Rv_like genotype and 14 S-like genotype. Conclusion: MIRU-VNTR typing has not been reported in any other study in Kenya and its higher discrimination can help identify genotypes that cannot be determined by spoligotyping. Association of Beijing genotype drug resistance particularly isoniazid should be of concern since it may result in multidrug resistance in the patients.展开更多
The present study investigates the genetic diversity among Mycobacterium tuberculosis complex circulating in the Centre region of Cameroon and analyzes the relationship between genotypes and drug resistance patterns. ...The present study investigates the genetic diversity among Mycobacterium tuberculosis complex circulating in the Centre region of Cameroon and analyzes the relationship between genotypes and drug resistance patterns. Spoligotyping was performed by PCR-amplification followed by the reverse hybridization of 298 cultured specimens. Spoligotypes patterns were identified by comparison to reference strains in SPolDB4 database via the MIRU VNTR plus web application. About 97.65% of all tuberculosis (TB) cases were attributed to M. tuberculosis. A total of 65 different profiles were identified. Of these, 40 were represented as Shared Types (ST) while the others were orphans. LAM10_CAM and Haarlem families were the most prevalent genetic families with 51.01% and 14.09% respectively. ST 61, a member of the LAM10_ CAM family formed the largest cluster with 128 (42.95%) isolates. No association was found between genotypes with regard to drug resistance and HIV sero-status. However, there was a significant association between genotypes and age groups. Patients belonging to 15 - 24 and 35 - 44 age groups were more likely infected by LAM10_CAM strains compared to others. The population structure of Mycobacterium tuberculosis complex strains from the Centre region was found to be diverse and the spoligotype 61 of the LAM10_CAM family was highly predominant. Isolates of the LAM10_CAM seem to be not associated with drug resistance.展开更多
The aim of this study was to investigate the usefulness of combining profiles obtained by using a line probe assay (LPA) originally intended to characterize the resistance of two major anti-tuberculosis drugs to the a...The aim of this study was to investigate the usefulness of combining profiles obtained by using a line probe assay (LPA) originally intended to characterize the resistance of two major anti-tuberculosis drugs to the association of spoligotyping and MIRU-VNTR, in order to improve its discriminatory power. For this purpose, 74 strains of Mycobacterium tuberculosis belonging to the same cluster after spoligotyping were further typed by using the 24 loci MIRU/VNTR. These strains were then tested by the GenoType MTBDRplus, and profiles obtained were analyzed within previously obtained clusters. The combination of spoligotying and MIRU-VNTR led to the consolidation of 56 of them (75.7%) in 9 clusters. Most of the strains (54, 96.4%) were multidrug resistant (MDR). From the 9 initial clusters, the addition of GenoType MTBDRplus helped to define 26 profiles including 11 unique profiles, and 3 original clusters remained undifferentiated. Results obtained express the relevance of combining this method which improved quite significantly the discriminatory power in typing Mycobacterium tuberculosis.展开更多
文摘Background: Molecular typing allows a rapid and precise species differentiation and is essential in investigating the spread of specific genotypes and any relationship with drug resistance. Methodology: To compare the discrimination power of 24-loci Mycobacteria interspersed repetitive units-variable number of tandem repeat (MIRU-VNTR) to spoligotyping in determining the circulating genotypes of Mycobacterium tuberculosis in isolates from pulmonary tuberculosis patients in Kenya, a total of 204 isolates were typed. Results: Spoligotyping identified 22 spoligo lineages;while 36(17.6%) isolates were not determined. MIRU-VNTR typing identified 12 genotypes;Kenya H37_Rv_ like, S-like that had never been reported before and which were not identified by spoligotyping were identified. Others were Uganda I and II, LAM, Beijing, TUR, EAI, Delhi/C, S and Haarlem. Only 8 (3.9%) were not defined by MIRU-VNTR. Delhi/CAS, EAI, S, S-like, LAM and Beijing had strains that showed resistance to all the five drugs tested. Two strains of EAI and 2 of S genotypes were resistant to all the five drugs tested. Beijing genotype commonly associated with drug resistance was found to be third in drug resistance (14.7%) after Delhi/CAS (28.9%) and LAM (17.6%) with the highest resistance towards isoniazid and pyrazinamide (3.9% each). MIRU-VNTR typing was more discriminative than spoligotyping;identifying 10 unique H37_Rv-like isolates designated KeniaH37_Rv_like genotype and 14 S-like genotype. Conclusion: MIRU-VNTR typing has not been reported in any other study in Kenya and its higher discrimination can help identify genotypes that cannot be determined by spoligotyping. Association of Beijing genotype drug resistance particularly isoniazid should be of concern since it may result in multidrug resistance in the patients.
文摘The present study investigates the genetic diversity among Mycobacterium tuberculosis complex circulating in the Centre region of Cameroon and analyzes the relationship between genotypes and drug resistance patterns. Spoligotyping was performed by PCR-amplification followed by the reverse hybridization of 298 cultured specimens. Spoligotypes patterns were identified by comparison to reference strains in SPolDB4 database via the MIRU VNTR plus web application. About 97.65% of all tuberculosis (TB) cases were attributed to M. tuberculosis. A total of 65 different profiles were identified. Of these, 40 were represented as Shared Types (ST) while the others were orphans. LAM10_CAM and Haarlem families were the most prevalent genetic families with 51.01% and 14.09% respectively. ST 61, a member of the LAM10_ CAM family formed the largest cluster with 128 (42.95%) isolates. No association was found between genotypes with regard to drug resistance and HIV sero-status. However, there was a significant association between genotypes and age groups. Patients belonging to 15 - 24 and 35 - 44 age groups were more likely infected by LAM10_CAM strains compared to others. The population structure of Mycobacterium tuberculosis complex strains from the Centre region was found to be diverse and the spoligotype 61 of the LAM10_CAM family was highly predominant. Isolates of the LAM10_CAM seem to be not associated with drug resistance.
基金the support of the European Respiratory Society,Fellowship STRTF 413-2011.
文摘The aim of this study was to investigate the usefulness of combining profiles obtained by using a line probe assay (LPA) originally intended to characterize the resistance of two major anti-tuberculosis drugs to the association of spoligotyping and MIRU-VNTR, in order to improve its discriminatory power. For this purpose, 74 strains of Mycobacterium tuberculosis belonging to the same cluster after spoligotyping were further typed by using the 24 loci MIRU/VNTR. These strains were then tested by the GenoType MTBDRplus, and profiles obtained were analyzed within previously obtained clusters. The combination of spoligotying and MIRU-VNTR led to the consolidation of 56 of them (75.7%) in 9 clusters. Most of the strains (54, 96.4%) were multidrug resistant (MDR). From the 9 initial clusters, the addition of GenoType MTBDRplus helped to define 26 profiles including 11 unique profiles, and 3 original clusters remained undifferentiated. Results obtained express the relevance of combining this method which improved quite significantly the discriminatory power in typing Mycobacterium tuberculosis.
